diff options
Diffstat (limited to 'pkg/sentry/mm')
| -rw-r--r-- | pkg/sentry/mm/mm.go | 8 | ||||
| -rw-r--r-- | pkg/sentry/mm/syscalls.go | 13 |
2 files changed, 21 insertions, 0 deletions
diff --git a/pkg/sentry/mm/mm.go b/pkg/sentry/mm/mm.go index 8c9f11cce..43567b92c 100644 --- a/pkg/sentry/mm/mm.go +++ b/pkg/sentry/mm/mm.go @@ -235,6 +235,14 @@ type MemoryManager struct { // vdsoSigReturnAddr is the address of 'vdso_sigreturn'. vdsoSigReturnAddr uint64 + + // membarrierPrivateEnabled is non-zero if EnableMembarrierPrivate has + // previously been called. Since, as of this writing, + // MEMBARRIER_CMD_PRIVATE_EXPEDITED is implemented as a global memory + // barrier, membarrierPrivateEnabled has no other effect. + // + // membarrierPrivateEnabled is accessed using atomic memory operations. + membarrierPrivateEnabled uint32 } // vma represents a virtual memory area. diff --git a/pkg/sentry/mm/syscalls.go b/pkg/sentry/mm/syscalls.go index a2555ba1a..0a66b1cdd 100644 --- a/pkg/sentry/mm/syscalls.go +++ b/pkg/sentry/mm/syscalls.go @@ -17,6 +17,7 @@ package mm import ( "fmt" mrand "math/rand" + "sync/atomic" "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" @@ -1274,3 +1275,15 @@ func (mm *MemoryManager) VirtualDataSize() uint64 { defer mm.mappingMu.RUnlock() return mm.dataAS } + +// EnableMembarrierPrivate causes future calls to IsMembarrierPrivateEnabled to +// return true. +func (mm *MemoryManager) EnableMembarrierPrivate() { + atomic.StoreUint32(&mm.membarrierPrivateEnabled, 1) +} + +// IsMembarrierPrivateEnabled returns true if mm.EnableMembarrierPrivate() has +// previously been called. +func (mm *MemoryManager) IsMembarrierPrivateEnabled() bool { + return atomic.LoadUint32(&mm.membarrierPrivateEnabled) != 0 +} |